1. Field of the Invention
The present invention relates to a cyclone-type dust collecting apparatus for a vacuum cleaner, and more particularly, to a grill assembly of a cyclone-type dust collecting apparatus for separating dust or filth from the air whirling in the cyclone-type dust collecting apparatus.
2. Description of the Prior Art
A cyclone-type dust collecting apparatus separates particles from a fluid by using a centrifugal force. Due to its simple structure and high resistance to high temperature and high pressure, the cyclone-type dust collecting apparatus has been used in many industrial fields and even in a vacuum cleaner.
The vacuum cleaner having the cyclone-type dust collecting apparatus is constructed so that relatively large particles of contaminants are firstly filtered in the cyclone-type dust collecting apparatus before contaminant-laden air is directed to a paper filter of the cleaner body. In this arrangement, the amount of contaminants that have to be filtered by the paper filter decreases, and so the usable life of the paper filter is lengthened. Also, problems like suction force deterioration and motor overload, which are caused when the paper filter is blocked or filled with the contaminants, can be also prevented.
U.S. Pat. No. 6,195,835 (application Ser. No. 09/388,532) issued Mar. 6, 2001 to the same applicant discloses a vacuum cleaner having the above-described cyclone-type dust collecting apparatus.
FIG. 1 herein is a sectional view schematically showing the structure and operation of the cyclone dust collecting apparatus for a vacuum cleaner of the type disclosed in U.S. Pat. No. 6,195,835.
As shown in FIG. 1 of this application, the cyclone-type dust collecting apparatus 10 of the U.S. Pat. No. 6,195,835 is disposed on extension pipes 1a and 1b of the vacuum cleaner. By using a centrifugal force, the cyclone-type dust collecting apparatus 10 separates and collects dust and filth from contaminant-laden air that is drawn in through a suction port of the cleaner. The cyclone-type dust collecting apparatus 10 includes a cyclone body 20, a dust receptacle 30 and a grill assembly 40.
The cyclone body 20 has a first connection pipe 21 connected to the extension pipe 1a at the suction port of the cleaner, a second connection pipe 22 connected to the extension pipe 1b at a body of the cleaner, an air inlet 23 interconnected with the first connection pipe 21 and an air outlet 24 interconnected with the second connection pipe 22. The contaminant-laden air is drawn into the cyclone body 20 through the air inlet 23, forming a vortex of air.
The dust receptacle 30 is connected to the cyclone body 20, and collects the contaminants that are separated from the air by the centrifugal force of the vortex of air generated in the cyclone body 20.
The grill assembly 40 is disposed on the lower side of the air outlet 24 of the cyclone body 20, and has a grill supporting portion 41, a conical grill portion 42 and a cylindrical grill portion 43. The cylindrical grill portion 43 has a plurality of fine holes 43a formed therein, and a conical dust blocking plate 44 formed on an end.
In the vacuum cleaner having the cyclone-type dust collecting apparatus as described above, contaminant-laden air is drawn by the suction force generated at the suction port of the cleaner, and the air enters the cyclone body 20 through the first connection pipe 21 in a diagonal direction. The air is diagonally drawn into the cyclone body 20 in a helical whirling current that moves downward to the bottom of the dust receptacle 30. During this process, contaminants are separated from the air by the centrifugal force of the whirling air current, and they are collected in the dust receptacle 30 after falling along an inner wall of the dust receptacle 30. The air reaching the bottom of the dust receptacle 30 then turns in direction and moves upward in a smaller radius vortex, and flows from the outside of the cleaner body through the fine holes 43a of the grill assembly 40, through the air outlet 24 and the second connection pipe 1b. Thus, the contaminants entrained in the air are blocked at the fine holes 43a of the grill assembly 40, and fall into the dust receptacle 30. Relatively large particles of the contaminants are also blocked by the dust blocking plate 44 and thus, they are collected in the dust receptacle 30.
In the vacuum cleaner having the cyclone-type dust collecting apparatus described above, dust and filth entrained in the air drawn into the suction port of the cleaner are firstly filtered and collected by the cyclone-type dust collecting apparatus, and as a result, the amount of contaminants that the paper filter has to filter decreases, and the usable life of the paper filter is extended.
The vacuum cleaner having the cyclone-type dust collecting apparatus described above has some problems, however. That is, as the whirling air in the dust receptacle 30 flows through the plurality of fine holes 43a of the grill assembly 40, dust and minute particles of the contaminants become attached to the grill assembly 40. As additional dust and foreign substances attach to the overall area of the grill assembly 40 as time goes by, those substances clog the fine holes 43a and block the outflow of air. This air flow blockage causes problems like suction force deterioration and motor overload, and so it becomes necessary to remove the dust and filth regularly. In the conventional case, however, since the dust and filth is attached to the overall area of the grill assembly 40, it is quite tricky to completely remove the dust and filth from the grill assembly 40. Accordingly, it is necessary to either prevent the dust and filth from attaching to the grill assembly 40, or to allow dust and filth to attach only to a certain area of the grill assembly 40 for easy removal thereof.